Outer Hair Cell Motility

Outer hair cells (OHCs) are extremely versatile mechanical components of the cochlea. Sitting above the basilar membrane, they appear able to perceive its vibration through their mechanosensitive hair bundles and to feed back mechanical forces that enhance both its sensitivity and its frequency selectivity. They also receive an efferent nerve supply that may be used to modulate this response, and they may receive additional information from mechanoreceptive elements in their basolateral membrane. During the last 10 years they have been the subject of many experiments designed to discover just exactly how they generate mechanical forces and how these forces contribute to the micromechanics of the cochlea. If all the proposed mechanisms actually occur in vivo, then OHCs can boast a remarkable behavioral repertoire.